This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this project is to evaluate the expression of neurological and inflammatory mediators such as opioids, growth factors and cytokines in normal subjects versus low back pain (LBP) patients diagnosed with severe degenerative disc disease (DDD). Twenty LBP patients with DDD will be recruited from a population of patients scheduled for surgical treatment of this condition. All LBP patients will undergo magnetic resonance imaging (MRI) of the lumbar region, a comprehensive standardized physical therapy assessment, a past medical history, and a lumbar puncture to collect 10-20 cc of cerebrospinal fluid to be used for biochemical analyses. Pain-free control subjects with mild-to-no lumbar DDD (n=20) and pain-free subjects with moderate-to-severe DDD (n=20) will also be evaluated using the same methods for the LBP group. Data from the LBP patients will be compared to those from the control subjects to determine which physical therapy and biochemical differences are associated with pain. Comparisons between the two control groups will be done to evaluate differences associated with advanced degeneration alone (without pain).